Electrical switches are components of an electrical circuit having internal electrically conductive contacts to create electrically conductive connections (switching state “ON” or ON state) or disconnect these connections (switching state “OFF” or OFF state). In case of a current-carrying connection which needs to be separated, electrical current flows through the contacts until they are disconnected. When an inductive circuit is disconnected by using a switch, the current flowing through the contacts cannot decrease to zero immediately. In this case there is an arc formed between the contacts. The arc is a gas discharge in a non-conductive medium, for example air. In switches in alternating current operation (AC), the arc is quenched regularly at the zero-crossing point of the alternating current. Due to not having a zero-crossing point in switches in direct current operation (DC) when disconnecting the contacts (switching off) there are arcs formed which burn steadily provided that the arc voltage is significantly lower than the operating voltage. When the circuit is operated having sufficient current and voltage (typically at over 1 A and over 50V), the arc will not extinguish by itself. For this purpose, these switches are fitted with arc chutes for quenching the arc. The arcing time (the duration of the arc burning) should be kept as short as possible, because the arc generates a significant amount of heat, and it causes burning off the contacts and/or causes thermal load on the contact bridge in the switch and thus it causes a reduction of the service life of the switch. In case of two pole or multi-pole switches with two or more switching chambers, the arcs generate a corresponding higher amount of heat than in case of one pole switches. In this case it is especially important that the arc is quenched quickly.
Quenching the arc is accelerated generally by using a magnetic field with the polarity set up in a way to generate a driving force on the arc in the direction of the arc chutes. The size of the driving force depends on the strength of the magnet(s). Permanent magnets are generally used to create a strong magnetic field. Unfortunately the driving force of a magnetic field in the direction of the arc chutes is created only in case of a specific direction of current. In order to avoid the faulty installation of the switches due to incorrect polarity or in case of switches required for both directions of current, the switch should be able to quench the arc, which is created between the open contacts, quickly irrespective of the actual polarity. It would be especially desirable to have two pole switches with a structure not considerably more complex than one pole switches.